Numerous techniques exist to vary the power of a transmitter or transceiver operating within a communication system. For example, it is known that battery powered transceivers (subscriber units) may be instructed by a base unit (or repeater) to increase or decrease their transmitter power. Accordingly, upon receipt of an appropriate command code, the battery powered transceiver adjusts its transmitter power (up or down) by a predetermined amount. In this way, the operational life of the battery power subscriber units may be increased by permitting transmissions at reduced power when the battery powered subscriber units are near the base unit (or repeater). See U.S. Pat. No. 5,003,610 by Morris Et. Al., hereby incorporated by reference. In many instances though, to ensure reliable communications between portables or between a portable and a base, the radio is transmitting at maximum RF power. This drains current and shortens battery life. One way to resolve this problem would be to increase battery capacity, but that would negatively impact the cost, weight and size of the overall radio-battery combination. Furthermore, transmitting at maximum power would cause undue interference with other radios in a nearby system.
In many situations, however, the major share of communication activity takes place directly between subscriber units (i.e., subscriber-to-subscriber), and not subscriber-to-base. Thus, the energy saving advantage is lost at a time when it is most critical to insure maximized operational transceiver life. Mode slaved or user selectable RF power does not resolve the problem fully. In case of user selectable power, it relies on user intelligence to decide which power level to use for communication. Thus, a need exists for an RF power tuning device which resolves the problems discussed above.